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Hello Ed,
Correct me if i am wrong...but I think the code looks ahead, if you remove
bars from the end of your data then when the Red arrow drops away the
preceeding Green arrow may also disappear. This mean the Green Arrow depends
(at least some of the time) on future data.
Just place the code below ahead of the code and gradually remove bars from
the end of your chart to check for look ahead problems. If the display
changes ahead of the last bar your code looks ahead.
Z = Null;
LB =LastValue(BarIndex());
RM = Param("RemoveBars",0,0,1000,1);
O = IIf(BarIndex()>(LB-RM),Z,O);
H = IIf(BarIndex()>(LB-RM),Z,H);
L = IIf(BarIndex()>(LB-RM),Z,L);
C = IIf(BarIndex()>(LB-RM),Z,C);
best regards,
herman
-----Original Message-----
From: Ed [mailto:vvsignin@xxxxxxxxx]
Sent: Sunday, January 30, 2005 4:43 PM
To: amibroker@xxxxxxxxxxxxxxx
Subject: [amibroker] AFL code that is too good to be true
Has anyone looked at this pivot finder? I found it in the AFL library
and just from eyeballing these signals they are rediculously good,
almost too good. I just want to see others' experiences with this
code:
Details:
Formula name: Pivot Finder
Author/Uploader: Mark - (email hidden)
Date/Time added: 2004-07-19 01:06:36
Origin: This has got to be one of the best pivot finders I have found
yet. Nobody knows the author who wrote it.... Whoever you are thanks
a bunch!!
Keywords:
Level: semi-advanced
Flags: indicator
DISCLAIMER: Most formulas present in AFL on-line library are
submitted by the users and are provided here on an "as is" and "as
available" basis. AmiBroker.com makes no representations or
warranties of any kind to the contents or the operation of material
presented here. We do not maintain nor provide technical support for
3rd party formulas.
Download formula file | Delete formula
Description:
/* **********************************
Code to automatically identify pivots
********************************** */
// -- what will be our lookback range for the hh and ll?
farback=Param("How Far back to go",100,50,5000,10);
nBars = Param("Number of bars", 12, 5, 40);
// -- Title.
Title = Name() + " (" + StrLeft(FullName(), 15) + ") O: " + Open + ",
H: " + High + ", L: " + Low + ", C: " + Close;
// -- Plot basic candle chart
PlotOHLC(Open, High, Low, Close,
"BIdx = " + BarIndex() +
"\n" + "O = " + O + "\n"+"H = "+ H + "\n"+"L = " + L
+ "\n"+"C ",
colorBlack, styleCandle);
GraphXSpace=7;
// -- Create 0-initialized arrays the size of barcount
aHPivs = H - H;
aLPivs = L - L;
// -- More for future use, not necessary for basic plotting
aHPivHighs = H - H;
aLPivLows = L - L;
aHPivIdxs = H - H;
aLPivIdxs = L - L;
nHPivs = 0;
nLPivs = 0;
lastHPIdx = 0;
lastLPIdx = 0;
lastHPH = 0;
lastLPL = 0;
curPivBarIdx = 0;
// -- looking back from the current bar, how many bars
// back were the hhv and llv values of the previous
// n bars, etc.?
aHHVBars = HHVBars(H, nBars);
aLLVBars = LLVBars(L, nBars);
aHHV = HHV(H, nBars);
aLLV = LLV(L, nBars);
// -- Would like to set this up so pivots are calculated back from
// last visible bar to make it easy to "go back" and see the pivots
// this code would find. However, the first instance of
// _Trace output will show a value of 0
aVisBars = Status("barvisible");
nLastVisBar = LastValue(Highest(IIf(aVisBars, BarIndex(), 0)));
_TRACE("Last visible bar: " + nLastVisBar);
// -- Initialize value of curTrend
curBar = (BarCount-1);
curTrend = "";
if (aLLVBars[curBar] <
aHHVBars[curBar]) {
curTrend = "D";
}
else {
curTrend = "U";
}
// -- Loop through bars. Search for
// entirely array-based approach
// in future version
for (i=0; i<farback; i++) {
curBar = (BarCount - 1) - i;
// -- Have we identified a pivot? If trend is down...
if (aLLVBars[curBar] < aHHVBars[curBar]) {
// ... and had been up, this is a trend change
if (curTrend == "U") {
curTrend = "D";
// -- Capture pivot information
curPivBarIdx = curBar - aLLVBars[curBar];
aLPivs[curPivBarIdx] = 1;
aLPivLows[nLPivs] = L[curPivBarIdx];
aLPivIdxs[nLPivs] = curPivBarIdx;
nLPivs++;
}
// -- or current trend is up
} else {
if (curTrend == "D") {
curTrend = "U";
curPivBarIdx = curBar - aHHVBars[curBar];
aHPivs[curPivBarIdx] = 1;
aHPivHighs[nHPivs] = H[curPivBarIdx];
aHPivIdxs[nHPivs] = curPivBarIdx;
nHPivs++;
}
// -- If curTrend is up...else...
}
// -- loop through bars
}
// -- Basic attempt to add a pivot this logic may have missed
// -- OK, now I want to look at last two pivots. If the most
// recent low pivot is after the last high, I could
// still have a high pivot that I didn't catch
// -- Start at last bar
curBar = (BarCount-1);
candIdx = 0;
candPrc = 0;
lastLPIdx = aLPivIdxs[0];
lastLPL = aLPivLows[0];
lastHPIdx = aHPivIdxs[0];
lastHPH = aHPivHighs[0];
if (lastLPIdx > lastHPIdx) {
// -- Bar and price info for candidate pivot
candIdx = curBar - aHHVBars[curBar];
candPrc = aHHV[curBar];
if (
lastHPH < candPrc AND
candIdx > lastLPIdx AND
candIdx < curBar) {
// -- OK, we'll add this as a pivot...
aHPivs[candIdx] = 1;
// ...and then rearrange elements in the
// pivot information arrays
for (j=0; j<nHPivs; j++) {
aHPivHighs[nHPivs-j] = aHPivHighs[nHPivs-
(j+1)];
aHPivIdxs[nHPivs-j] = aHPivIdxs[nHPivs-(j+1)];
}
aHPivHighs[0] = candPrc ;
aHPivIdxs[0] = candIdx;
nHPivs++;
}
} else {
// -- Bar and price info for candidate pivot
candIdx = curBar - aLLVBars[curBar];
candPrc = aLLV[curBar];
if (
lastLPL > candPrc AND
candIdx > lastHPIdx AND
candIdx < curBar) {
// -- OK, we'll add this as a pivot...
aLPivs[candIdx] = 1;
// ...and then rearrange elements in the
// pivot information arrays
for (j=0; j<nLPivs; j++) {
aLPivLows[nLPivs-j] = aLPivLows[nLPivs-(j+1)];
aLPivIdxs[nLPivs-j] = aLPivIdxs[nLPivs-(j+1)];
}
aLPivLows[0] = candPrc;
aLPivIdxs[0] = candIdx;
nLPivs++;
}
}
// -- Dump inventory of high pivots for debugging
/*
for (k=0; k<nHPivs; k++) {
_TRACE("High pivot no. " + k
+ " at barindex: " + aHPivIdxs[k] + ", "
+ WriteVal(ValueWhen(BarIndex()==aHPivIdxs[k],
DateTime(), 1), formatDateTime)
+ ", " + aHPivHighs[k]);
}
*/
// -- OK, let's plot the pivots using arrows
PlotShapes(
IIf(aHPivs==1, shapeDownArrow, shapeNone), colorRed, 0,
High, Offset=-15);
PlotShapes(
IIf(aLPivs==1, shapeUpArrow , shapeNone), colorGreen, 0,
Low, Offset=-15);
Formula:
/* **********************************
Code to automatically identify pivots
********************************** */
// -- what will be our lookback range for the hh and ll?
farback=Param("How Far back to go",100,50,5000,10);
nBars = Param("Number of bars", 12, 5, 40);
// -- Title.
Title = Name() + " (" + StrLeft(FullName(), 15) + ") O: " + Open + ",
H: " + High + ", L: " + Low + ", C: " + Close;
// -- Plot basic candle chart
PlotOHLC(Open, High, Low, Close,
"BIdx = " + BarIndex() +
"\n" + "O = " + O + "\n"+"H = "+ H + "\n"+"L = " + L
+ "\n"+"C ",
colorBlack, styleCandle);
GraphXSpace=7;
// -- Create 0-initialized arrays the size of barcount
aHPivs = H - H;
aLPivs = L - L;
// -- More for future use, not necessary for basic plotting
aHPivHighs = H - H;
aLPivLows = L - L;
aHPivIdxs = H - H;
aLPivIdxs = L - L;
nHPivs = 0;
nLPivs = 0;
lastHPIdx = 0;
lastLPIdx = 0;
lastHPH = 0;
lastLPL = 0;
curPivBarIdx = 0;
// -- looking back from the current bar, how many bars
// back were the hhv and llv values of the previous
// n bars, etc.?
aHHVBars = HHVBars(H, nBars);
aLLVBars = LLVBars(L, nBars);
aHHV = HHV(H, nBars);
aLLV = LLV(L, nBars);
// -- Would like to set this up so pivots are calculated back from
// last visible bar to make it easy to "go back" and see the pivots
// this code would find. However, the first instance of
// _Trace output will show a value of 0
aVisBars = Status("barvisible");
nLastVisBar = LastValue(Highest(IIf(aVisBars, BarIndex(), 0)));
_TRACE("Last visible bar: " + nLastVisBar);
// -- Initialize value of curTrend
curBar = (BarCount-1);
curTrend = "";
if (aLLVBars[curBar] <
aHHVBars[curBar]) {
curTrend = "D";
}
else {
curTrend = "U";
}
// -- Loop through bars. Search for
// entirely array-based approach
// in future version
for (i=0; i<farback; i++) {
curBar = (BarCount - 1) - i;
// -- Have we identified a pivot? If trend is down...
if (aLLVBars[curBar] < aHHVBars[curBar]) {
// ... and had been up, this is a trend change
if (curTrend == "U") {
curTrend = "D";
// -- Capture pivot information
curPivBarIdx = curBar - aLLVBars[curBar];
aLPivs[curPivBarIdx] = 1;
aLPivLows[nLPivs] = L[curPivBarIdx];
aLPivIdxs[nLPivs] = curPivBarIdx;
nLPivs++;
}
// -- or current trend is up
} else {
if (curTrend == "D") {
curTrend = "U";
curPivBarIdx = curBar - aHHVBars[curBar];
aHPivs[curPivBarIdx] = 1;
aHPivHighs[nHPivs] = H[curPivBarIdx];
aHPivIdxs[nHPivs] = curPivBarIdx;
nHPivs++;
}
// -- If curTrend is up...else...
}
// -- loop through bars
}
// -- Basic attempt to add a pivot this logic may have missed
// -- OK, now I want to look at last two pivots. If the most
// recent low pivot is after the last high, I could
// still have a high pivot that I didn't catch
// -- Start at last bar
curBar = (BarCount-1);
candIdx = 0;
candPrc = 0;
lastLPIdx = aLPivIdxs[0];
lastLPL = aLPivLows[0];
lastHPIdx = aHPivIdxs[0];
lastHPH = aHPivHighs[0];
if (lastLPIdx > lastHPIdx) {
// -- Bar and price info for candidate pivot
candIdx = curBar - aHHVBars[curBar];
candPrc = aHHV[curBar];
if (
lastHPH < candPrc AND
candIdx > lastLPIdx AND
candIdx < curBar) {
// -- OK, we'll add this as a pivot...
aHPivs[candIdx] = 1;
// ...and then rearrange elements in the
// pivot information arrays
for (j=0; j<nHPivs; j++) {
aHPivHighs[nHPivs-j] = aHPivHighs[nHPivs-
(j+1)];
aHPivIdxs[nHPivs-j] = aHPivIdxs[nHPivs-(j+1)];
}
aHPivHighs[0] = candPrc ;
aHPivIdxs[0] = candIdx;
nHPivs++;
}
} else {
// -- Bar and price info for candidate pivot
candIdx = curBar - aLLVBars[curBar];
candPrc = aLLV[curBar];
if (
lastLPL > candPrc AND
candIdx > lastHPIdx AND
candIdx < curBar) {
// -- OK, we'll add this as a pivot...
aLPivs[candIdx] = 1;
// ...and then rearrange elements in the
// pivot information arrays
for (j=0; j<nLPivs; j++) {
aLPivLows[nLPivs-j] = aLPivLows[nLPivs-(j+1)];
aLPivIdxs[nLPivs-j] = aLPivIdxs[nLPivs-(j+1)];
}
aLPivLows[0] = candPrc;
aLPivIdxs[0] = candIdx;
nLPivs++;
}
}
// -- Dump inventory of high pivots for debugging
/*
for (k=0; k<nHPivs; k++) {
_TRACE("High pivot no. " + k
+ " at barindex: " + aHPivIdxs[k] + ", "
+ WriteVal(ValueWhen(BarIndex()==aHPivIdxs[k],
DateTime(), 1), formatDateTime)
+ ", " + aHPivHighs[k]);
}
*/
// -- OK, let's plot the pivots using arrows
PlotShapes(
IIf(aHPivs==1, shapeDownArrow, shapeNone), colorRed, 0,
High, Offset=-15);
PlotShapes(
IIf(aLPivs==1, shapeUpArrow , shapeNone), colorGreen, 0,
Low, Offset=-15);
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